JPH0526896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power shovel automatic excavation device.

BACKGROUND ART Conventionally, in order to automate excavation work in a power shovel, it is known that position detectors are provided in each part of the work machine, and a work machine operating valve is controlled based on position control detected by these position detectors.
However, with this method, the precision of the potentiometer used in the position detector is not sufficient, so highly accurate position detection cannot be performed, and the driving force is not large enough for the inertia of the work equipment to be controlled, resulting in deterioration of dynamic characteristics. Furthermore, since the stroke of the hydraulic cylinder is non-linear with respect to the angle of the working machine, there is a problem in that highly accurate control cannot be achieved by simply detecting the position of the working machine.

This invention was made for the purpose of improving such problems, and in addition to detecting the position of each part of the work machine, it also detects the spool position of the work machine operation valve, and controls each operation valve from the spool position and time. The purpose of this project is to provide a power swivel automatic excavation device that enables high control over the excavation system.

The present invention will be described in detail below with reference to one embodiment.
In the figure, reference numeral 1 denotes a lower vehicle body that can move freely by the suspension 2. An upper rotating body 4 is provided on the lower vehicle body 1 via a rotating mechanism 3, and a working machine 5 is attached to the front of the upper rotating body 4. is installed. The working machine 5 is attached to a poom 7 which can be raised and lowered freely by a poom cylinder 6, and is attached to the tip of this poom 7, and is attached to an arm 9 which can be rotated by an arm cylinder 8 and to the tip of the arm 9, and can be rotated by a bucket cylinder 10. It consists of an actual bucket 11, and each cylinder 6,
8, 10 and the swing motor 12 have a pressure compensation valve 13,
Each work machine operating valve 17,
Hydraulic pressure is supplied from 18, 19, and 20. Further, each operating valve 17 to 20 is connected to a spool 17a to 20a by a servo motor 21, 2.
2, 23, and 24 are interlocked, and each servo motor 21 to 24 controls the stroke of the spool 17a to 20a by a signal inputted from a motor control circuit 25 via a motor drive circuit 26. Each spool 17a to 20a is provided with a position detector 27,
These position detectors 27 detect the position of each spool 17a to 20a, and the position signals detected by the position detectors 27 are as follows.
The signal is input to a control circuit 31 via each pivot of the working machine 5 and a position detector 28 provided in the swing mechanism 3, a multi-breather 29, and an A/D converter 30. The control circuit 31 includes a central processing unit 32, a storage device 33, an input device 34, a display device 35, an emergency stop switch 36, an alarm 37, etc.
Signals from pressure switches 38 provided in the work machine operating valves 17 to 20 are also input via a pressure switch interface 39 to control the work machine 5 as follows.

Next, the operation will be explained according to the flowchart shown in FIG. 3. When performing automatic excavation by the working machine 5, first, the automatic excavation operation is stored in the storage device 33 in the control circuit 31 through a learning process. A memorization operation is required. The learning process is selected in a step after the start, and TEACH is displayed on the display device 35. Thereafter, when the process starts in step, the positions of the various parts of the working machine 5 before work are detected by the position detectors 28 and stored in the storage device 33. After that, when the operator operates the operating lever 40 to perform excavation work,
Changes in the position of each part of the work machine 5 and the accompanying operation valve 17
The positions of the spools 2 to 20 are detected by the position detectors 27 and 28 over time and stored (step). Next, the process advances to the step to determine whether the time has elapsed, and if the time has not exceeded, the process proceeds to the step to take time until the next measurement, and then returns to the step to determine whether the work is complete. If the learning work has been completed, the process proceeds to step, where the position of each part of the working machine 5 after the work is completed is detected by the position detector 28, and the position is memorized.

After completing the learning process as described above, proceed to the reproduction process in steps.

In the reproduction process, first, the number of times of work is input in a step, and the work is started in a step.

To start work, first step work machine 5
The current position of each part is detected by the position detector 28 provided in each part of the work machine 5, and the central processing unit 32 detects the current position of each part.
In step, the central processing unit 32 determines whether the position is the same as the position before the start of learning stored in the learning storage device 33. If the position is not the same, the process advances to step and each part of the work implement 5 is trained. The position is corrected so that it is in the same position as at the start.

The position of the work machine 5 is corrected based on the position of each work machine 5 before the start of learning, which was stored in the storage device 33 during learning, and the position of the work machine 5 detected by the position detector 28 at the time of starting reproduction.
This is performed by the central processing unit 32 comparing the positions of each part, calculating the deviation, and outputting a control signal corresponding to the deviation to the motor control circuit 25.

The motor control circuit 25 moves the spools 17a to 20a of the operation valves 17 to 20 using the servo motors 21 to 24 based on the control signal output from the central processing unit 32, and moves the cylinders of each part of the work machine 5 in a direction where deviation is eliminated. 6, 8, 10 and the swing motor 12.

Also, while the position is being corrected, return to step 5 and
The position of each part is continuously detected by the position detector 28, and when the position of each part of the working machine 5 reaches the same position as at the start of learning, the position correction operation is completed and automatic excavation is started.

In automatic excavation, first, in a step, the number of operations input in the step is displayed as a point decrement, and along with automatic excavation, the position of each part of the step work machine 5 is detected by the position detector 28.

Then, in a step, the central processing unit 32 compares and calculates the position data of each part of the working machine 5 stored in the learning storage device 33 and the position data sent by the position detector 28 over time, and calculates a difference between the two data. If so, a correction amount for correcting the deviation is calculated.

In addition, the causes of discrepancies between the position data of each part of the work machine 5 memorized during learning and the position data during reproduction include changes in circuit resistance due to changes in oil viscosity, and changes in the soil quality of the ground to be excavated. and so on.

On the other hand, the positional deviation of each part of the working machine 5 is corrected in a step based on the correction amount calculated in the step, and each part of the working machine 5 is corrected to the position stored at the time of learning, and automatic excavation continues.

Even during automatic excavation, the position detector 28 detects the position of each part of the working machine 5 in steps, and if a deviation occurs between the position data and the position data stored during learning, it is corrected each time in steps.

Then, in the step, it is determined whether one cycle of work is completed for each work, and if it is not completed, the process returns to the step and repeats the above operation, and if it is completed, the process proceeds to the step and - from the set number of times.
1 and then proceed to step 〓〓 to determine whether the set number of operations have been completed. If not completed, step
Go to and repeat the above operation, and if completed, return to the start and finish the work.

If the content of the work changes thereafter, automatic excavation will proceed through a new learning process, and manual operation is also possible at any time by inputting an interrupt signal, as shown in the flowchart shown in FIG.

As described in detail above, this invention enables automatic excavation to be performed in accordance with the content by learning and memorizing the work content in advance during automatic excavation. The flow rate of hydraulic pressure supplied to each hydraulic cylinder and swing motor is controlled based on the relationship between the spool position and time based on the signal from the position detector installed in the This enables automatic excavation with higher precision than that which is controlled based on signals from an installed position detector.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is an overall configuration diagram including the control system, Fig. 2 is a plan view of the power shovel, Fig. 3 is a flowchart showing automatic excavation operation, and Fig. 4 is a manual diagram. It is a flowchart showing the operation. 1 is the lower body, 2 is the suspension, 3 is the turning mechanism,
4 is an upper revolving body, 5 is a work machine, 17 to 20 are work machine operation valves, 17a to 20a are spools,
22 to 24 are servo motors, 27 and 28 are position detectors, 31 is a control circuit, and 33 is a storage device.

Claims (1)

[Claims] 1. An upper revolving body 4 that is rotatably provided on a lower vehicle body 1 that is self-propelled by an undercarriage 2 via a revolving mechanism 3, a working machine 5 attached to the upper revolving body 4, and the upper revolving body 4. 4. Swivel operation and work equipment 5
In a power swivel equipped with a plurality of work equipment operation valves 17 to 20 that control the operation of the swing mechanism 3 and the work equipment 5, the valves are provided in each part of the swing mechanism 3 and the work equipment 5, and are arranged to control the swing position of the upper revolving body 4 and the operating position of each part of the work equipment 5. a position detector 28 for detecting the
7 to 20, and the servo motor 22
a position detector 27 that detects the positions of the spools 17a to 20a controlled by the spools 17a to 24; a storage device 33 that stores the rotational position of the upper revolving structure 4 and the position of each part of the working machine 5 over time during the learning process; During automatic excavation, the learning position data stored in the storage device 33 and the position detector 2
The positions of the parts of the revolving upper structure 4 and the working machine 5 detected by the parts 7 and 28 are compared and calculated over time, so that each part of the revolving upper structure 4 and the working machine 5 operates with the same operation based on the content memorized during learning. Work equipment operation valve 1
An automatic power shovel excavation device comprising a control circuit 31 for controlling servo motors 22 to 24 provided at ports 7 to 20.